Prefabricated reinforced concrete wall panel and installation method

ABSTRACT

A prefabricated reinforce concrete wall panel having a curb wall at the top and anchoring loops embedded in the panel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from the prior U.S. Provisional Patent Application No. 61,763,708, filed on Feb. 12, 2013, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to prefabricated reinforced concrete wall panels and to a precast frost wall system comprising a plurality of interconnected standardized steel reinforced concrete panels.

BACKGROUND OF THE INVENTION

Building structures, particularly frost wall systems, are sometimes constructed using prefabricated reinforced concrete wall panels (hereinafter referred to as “panels”). These panels are manufactured at a remote plant facility and are delivered to the job site for installation as will be described.

The standardized panel according to this invention is intended to improve the current methods of construction of frost wall systems which are heavily labour intensive. The use of the panel is intended to reduce field man hours, installation steps and lessen potential exposure to variable environmental factors which can further delay an installation.

The current method of construction for frost wall foundations is labour intensive requiring multiple trades and involves separate and discrete building and erecting sequences. Periods of inactivity are also dictated to allow for concrete curing which adds delay. The object of the present invention is to reduce the overall field man hours required for construction of a frost wall foundation. Typically, a prior art frost wall foundation is constructed in four mobilizations. Day 1 mobilization involves the excavation of a trench. A crew follows behind to form a footing base. Thereafter, weather permitting, the footings are poured and left to cure overnight. It is a requirement to allow the footing base to cure because a solid level surface is required to support the wall forming system.

Day 2, the footing base forms are stripped, stacked and removed from the site. The foundation, and piers if required, are formed and poured. All door opening wall drops must be laid out and formed in advance so that when the slab on grade is poured, concrete is placed over the wall top so as to create a seamless transition. An alternate method is a masonry block foundation where blocks are individually stacked and mortared together. Day 3, the foundation and pier forms are stripped, stacked and loaded for removal and the foundation trench is backfilled. The process of backfilling may be further postponed under a masonry block foundation approach. A final strip on the 4^(th) mobilization is required to clean up and remove forms, braces and waste as well as address any deficiencies to the formed concrete surface such as grinding, fins, parging and repairing tie hole penetrations. Reducing the number of steps and the travel and limiting the number of trades on a site is advantageous to cost effective construction.

One of the challenges of on site poured concrete is to achieve a level of uniformity throughout a project and providing an end product that is free from improper consolidation of the concrete or “honeycombing” and “bug holes” or fins. Creating a smooth faced wall free from defects with a constant consistency of colour and precision is difficult to attain in the field.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a prefabricated reinforced concrete wall panel is provided having opposed faces, a top, a bottom, a height, a length, and a width. The panel comprises a curb wall portion at the top of the panel, having a curb height, a thickness less than the width of the panel, and a ledge, defining an open recess in the panel above the ledge. A first anchoring loop is embedded in the panel and extends outwardly from the bottom thereof, and a second anchoring loop is embedded in the panel and extends into the recess, but not above the top of the panel.

According to another aspect of the present invention, a prefabricated reinforced concrete wall panel is provided having opposed faces, a top, a bottom, a height, a length, and a width. The panel comprises a curb wall portion at the top of the panel, having a curb height, a thickness less than the width of the panel, and a ledge, defining an open recess in the panel above the ledge. A first anchoring loop is embedded in the panel and extends outwardly from the bottom thereof, and a second anchoring loop is embedded in the panel and extends into the recess, but not above the top of the panel. The face of the panel intersecting said ledge has thereon spaced apart recesses having a depth less than the width of the panel.

According to yet another aspect of the present invention, a method of building a perimeter structure section is provided, comprising the steps of excavating a perimeter trench, providing a plurality of prefabricated reinforced concrete wall panels to frame the perimeter structure, positioning and aligning said panels in said trench, pouring a concrete footing in said trench such that the anchoring loops below the bottom of the panel are wet set in the footing, and curing said concrete footing, thereby integrally connecting the panels to one another and the concrete footing.

In order that the invention may be more clearly understood, a preferred embodiment(s) thereof will now be described in detail by way of example, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective drawing of a panel according to the present invention.

FIG. 2 is a cross sectional, partly sectional view of a panel connected to the footing at the bottom and the on grade slab at the top according to one aspect of the present invention.

FIG. 3 is an alternate embodiment of the present invention wherein the top of the panel is adapted with a double curb wall.

FIG. 4 is a cross sectional, partly sectional view of the leveling rod arrangement.

Further features of the invention will be described or will become apparent in the course of the following detailed description.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, the panel 1 is a prefabricated reinforced concrete panel having a height h, length, width w, and a curb wall portion 2 at the top across the length of the panel. The curb wall portion 2 has a horizontal ledge 3 defining an open recess in the panel 1 above the ledge 3.

During fabrication of the panel 1, the anchoring loops 8 are embedded in the panel 1 at the top and bottom extending above into the open recess, but not above the top of the panel 1, and extending below outwardly from the bottom of the panel 1.

The top and bottom anchoring loops 8 are thus formed at regularly spaced intervals along the ledge 3 and underneath the bottom of the panel 1 and are used to wet set the panel 1 in the footings and on grade slab when poured.

The panel 1 has an exterior facing wall and an interior facing wall. The interior facing wall of the panel 1 is provided with regularly spaced indentations separated by vertical and horizontal chord elements 4 and 5 respectively. The chord elements 4 and 5 are portions of the panel 1 of a thickness substantially equal to the width w. The indentations, as shown in FIG. 1, are preferably rectangular-like and have a width wc that is less than the width w of the panel 1. The purpose of the indentations is to eliminate dead weight panel concrete material that is not required for structural purposes.

Preferably, the panel 1 is reinforced with reinforcing steel as in known in the art and, by way of example, as described herein. The steel reinforcements 6 and 7 are preferably embedded within the panels during manufacture and made of steel with suitable structural characteristics for concrete reinforcement in building structures as is known in the art. However, the panels 1 may be reinforced with polymers, alternate composite material, or any suitable material known in the art for use in reinforcing concrete building elements.

The curb wall portion 2 and top and bottom horizontal chord elements 5 have steel reinforcements 7 along their lengths as do the vertical chord elements 4. Steel reinforcements 6 are shown in dotted lines, by way of example, at one chord location. Preferably, the steel reinforcements 6 embedded within the vertical chord elements 4 comprise a single continuous loop that forms the anchoring loops 8.

One advantage of the curb wall portion 2 is to permit onsite cutting of wall drops for door or entry locations at any desired position along the length of the panel 1. A concrete saw is used to cut a wall drop between locations a and b. After the cut, a hammer is used to remove the intermediate curb concrete. In the prior art, the wall drop locations would have to be individually framed and additional labour is thus eliminated by the use of the panels according to this invention.

To install the panels 1, a trench is excavated using known methods. The panels 1 are lowered into position by means of a crane or boom and aligned, braced and leveled in situ. The footings 13 are poured. The anchoring loops 8 below the bottom of the panel 1 are thereby wet set in the footings 13 and become structurally and integrally connected thereto when the concrete cures. Thereafter, the on grade slab 14 is poured and similarly the anchoring loops 8 in the recess at the top of the panel 1 are wet set and are integrally connected to the on grade slab 14 when the concrete is cured. In this way the panels 1 are permanently and structurally connected to the footings 13 and on grade slab 14 to complete the installation. The interconnection of these elements, as disclosed above, is shown in FIG. 2.

In one embodiment, precise horizontal leveling of the panels 1 in the trench may be effected as follows. The panels 1 are first lowered into the trench by means of a crane. Preferably, as shown in FIG. 1, a panel 1 is cable connected to an I-beam 12 by means of the anchoring loops 8 in the recess at the top of the panel 1, as shown, and the crane acts on the combination to lower the panel 1 into the trench. Initially, with the aid of transits and levels, the panel 1 is guided into approximate alignment and temporarily braced. Final alignment is effected with leveling rods 10, as described.

Referring to FIG. 4, threaded holes 9 are provided in the bottom horizontal chord element 5 of the panel 1 to permit a complementarily threaded leveling rod 10 to turn therein. Bearing blocks 11 are placed underneath the leveling rod 10 in the footing frame and are used to support the bottom end of the leveling rod 10. Rotation of the fore or aft leveling rods 10 will effect precise accurate adjustments to level the panel 1.

Adjacent panels 1 may be fastened end to end by means of alignment holes precisely located in the vertical chord elements 4 of the panel 1. A bolt and nut fastening means will temporarily hold the panels 1 together until the concrete is poured into the footing 13.

It is to be noted that the panel 1 according to this invention may be cut to length on the job site which is another advantage of the present invention.

FIG. 3 illustrates an alternate embodiment of the present invention, wherein the top of the panel 1 is adapted with a double curb wall portion 15 for installations where the interior slab on grade 14 is poured flush with the bottom of the open recess to interior curb wall 15 to act as an interior bumper surface which is typical of structures that have specific traffic that may come in contact with the outer wall of the structure.

This is also a common practice for wood frame buildings where it is beneficial to elevate the lumber framing members away from the moist conditions found at grade level. As discussed with reference to FIG. 1, the entrance may be saw-cut vertically and the unneeded section of curb can be removed without difficulty with a hammer to create wall drops anywhere within a panel length. Anchor bolts 16 connect the foundation wall to the building components such as lumber or steel studs and are wet set, as is known in the art, and located in the open recess between the curb walls of the double curb wall portion 15.

In another embodiment, rigid insulation can be placed vertically and horizontally in the open recess to create a thermal break when the slab on grade is poured. The anchoring loops 8 extend beyond the insulation and act to structurally connect the slab on grade to the panel, as discussed.

Other advantages which are inherent to the invention are obvious to one skilled in the art. The embodiments are described herein illustratively and are not meant to limit the scope of the invention as claimed. Variations of the foregoing embodiments will be evident to a person of ordinary skill and are intended by the inventor to be encompassed by the following claims. 

What is claimed is:
 1. A prefabricated reinforced concrete wall panel having opposed faces, a top, a bottom, a height, a length, and a width, comprising: a curb wall portion at the top of the panel, having a curb height, a thickness less than the width of the panel, and a ledge, defining an open recess in the panel above the ledge, and a first anchoring loop embedded in the panel and extending downwardly from the bottom thereof, and a second anchoring loop embedded in the panel and extending into the recess, but not above the top of the panel.
 2. The panel of claim 1, wherein the face intersecting said ledge has thereon spaced apart recesses having a depth less than the width of the panel.
 3. The wall panel of claim 2, having one or more threaded holes extending between said recesses and the bottom of the panel adapted to threadably receive threaded rods therein for variable threadable extension of the rod below the bottom of the panel.
 4. The wall panel of claim 1, wherein said curb wall portion comprises a double spaced apart curb wall, each having a curb height and a thickness less than half of the width of the panel, and a ledge, defining an open recess in the panel, above the ledge, between the two curb walls.
 5. The wall panel of claim 4, further comprising anchors wet set in concrete poured into the open recess between the two curb walls and extending above the top of said curb walls, for attachment to building components.
 6. The wall panel of claim 1, further comprising insulation along the interior of said open recess, wherein said anchoring loops extend beyond said insulation.
 7. A method of building a perimeter structure section, comprising the steps of: excavating a perimeter trench; providing a plurality of prefabricated reinforced concrete wall panels according to claim 1 to frame the perimeter structure; positioning and aligning said panels in said trench; pouring a concrete footing in said trench such that the anchoring loops below the bottom of the panel are wet set in the footing; and curing said concrete footing, thereby integrally connecting the panels to one another and the concrete footing.
 8. The method of claim 7, further comprising the step of cutting and removing a section of said curb wall portion to create a wall drop in the panel.
 9. The method of claim 7, further comprising the steps of: pouring a concrete slab level with the top of the panels such that the anchoring loops at the top of the wall panel are we set in said concrete slab; and curing said concrete slab, thereby integrally connecting the wall panels to one another, said concrete footing, and said concrete slab.
 10. The method of claim 7, wherein the step of providing a plurality of prefabricated reinforced concrete wall panels according to claim 1 is replaced with the step of providing a plurality of prefabricated reinforced concrete wall panels according to claim 3 and the step of positioning said panels in said trench comprises, for each of said panels, the steps of: attaching said panel to a crane; lowering said panel into said trench; roughly positioning said panel in the desired position within said trench; temporarily bracing said panel; and adjusting the positioning of said panel using said leveling rods.
 11. The method of claim 7, wherein the step of providing a plurality of prefabricated reinforced concrete wall panels according to claim 1 comprises the steps of: providing a plurality of panels according to claim 1 of a standard length; and cutting said panels of a standard length to the desired length. 